Float glass is usually manufactured by continuously pouring the molten glass onto a tin bath, which is heated in an elongate tub, and the thus resulting glass strip.
The subsequent making up of float glass is carried out by longitudinal cutting and transverse cutting of the glass strip which emerges from the float glass production at a particular feed rate. The longitudinal cutting in this case is effected by longitudinal cutting wheels which are located in corresponding positions above the glass strip. The transverse cutting, or cutting to length, occurs with the aid of cutting bridges and transverse cutting wheels which are moved transversely on said cutting bridges across the glass strip. The glass panels to be cut are usually cut from float glass having a length of 6 m and a width of more than 3 m.
In the shaping of the glass strip, usually a somewhat different distribution of thickness is formed on the edges than in the center or the later net useable area as a result of surface tensions, temperature gradients and viscosity gradients and on account of mechanical conveying tools, for example rollers. The edge region on both sides of the glass strip here is referred to as the border region.
The object forming the basis of DE 102 37 478 B4 is thus to carry out the usual method for cutting a glass strip in respect of the applied cutting force in such a manner that the border region and also the net region are sufficiently scored in order to achieve a correct fracture process and simultaneously a premature breaking apart of the glass strip.
According to claim 1 of said document, the solution to this problem proceeds from a method for cutting a continuous glass strip in the manufacturing of flat glass, which has an inhomogeneous distribution of thickness across its width, in which further a cutting tool is moved across the width of the glass strip with a cutting force, which is predetermined by a control unit, creating a notch at an angle in relation to the conveying direction, and the glass strip is subsequently mechanically fractured along the notch. In such a method, protection is claimed for the cutting force to be actively predetermined by the control unit in a manner adapted to the thickness of the glass.
In another technical field, glass having particular optical functions, for example glass having as defined precise surface structuring, is often demanded, Such a structuring is inter alia demanded for display screens for flat screen monitors, referred to as channel plates.
DE 198 47 549 C1 discloses a shaping tool having a structured surface for creating structures on glass for manufacturing such display screens and the use of said shaping tool in the structuring of channel plates. This known shaping tool has a roll cylinder which consists of a metallic hollow cylinder on the outer sleeve of which a shaping sheet, which has recesses according to the negative of the glass structures to be applied, is attached in close two-dimensional contact. Furthermore, said tool has a shaft for the continuous drive of the roll cylinder, said shaft extending through the metallic hollow cylinder, wherein, level with the end face of the metallic hollow cylinder, two dogs which are in operative engagement in a form fitting manner with the hollow cylinder are fixedly attached to the shaft. The known tool further has an electric heating, which is located in an electrically isolated manner between the shaft and the metallic hollow cylinder and has an additional thermal insulation in relation to the shaft.
In the meantime, further possibilities for manufacturing glass having a structured surface on a float glass line have emerged; however, no printed documentation pertaining to them is available.
If there is now the requirement for one and the same float glass line to alternatingly produce and out to length glass having a smooth surface and glass having a structured surface, different installations are required for manufacturing glass having such differences. However, if an existing installation is used in this event, said installation, for example when changing over from normal glass to glass having a structured surface, needs to be equipped with a corresponding additional unit. Moreover, the old molten glass has no first cool down and the melting process then has to be started over again. In addition, glass having a structured surface has to be cut in a different manner than normal float glass.